High-yield reactive extraction of giant fullerenes from soot

By the common Soxhlet extraction with 1,2,4-trichlorobenzene a mere 8 mass % of virgin fullerene soot can be dissolved. The extracted soot was subjected to a reactive extraction with 5-hexadecanamido-1,3-dihydro-2-benzothiophene 2,2-dioxide(4), an ortho-quinodimethane precursor. Through an irreversible Diels–Alder cycloaddition an additional 12 mass % was solubilized. Mass spectrometry, vapour pressure osmometry and elemental analysis indicate that the soluble material consists of multiple adducts of fullerenes C 60 –C 418 .